Simple parking sensors should serve well. Autocop and Xenos are considered as reputed brands. It will cost less than Rs.5,000. But do remember that it might affect warranty. Please check this with the dealer and if it does, then it’s better to install from the dealership itself.
You can get them under Rs.5k but it also depends on the number of sensor(s) you want(IMO, 4 Sensors are enough). Autocop is a very reputed brand. If your car is in warranty, it may void the warranty. Do check with your tata/fiat dealership if they have sensors and better get it from the dealership itself.